Survivor: Thailand was the fifth season of the United States reality showSurvivor. It was filmed in the summer of 2002 and was shown on TV from September 19 – December 19, 2002 on CBS. It was set on the island of Ko Tarutao in Thailand. There were fourteen episodes, one being shown each week. The season started with two tribes; an orange tribe, Chuay Gahn (Thai: ช่วยกัน "to help one another") and a purple tribe, Sook Jai (สุขใจ "happy heart" ). Later, they merged (combined) into one tribe, which the players named "Chuay Jai", made by mixing the names Chuay Gahn and Sook Jai. On December 19, 2002, Brian Heidik won against Clay Jordan by a vote of 4-3 to become the sole survivor.

The season had many new gameplay twists. The first happened on Day 1, when the two oldest players, Jake Billingsley and Jan Gentry, were given the power to pick their own tribes. This was the first time in Survivor history that the two starting teams were not chosen by the producers. The second was an offer of mutiny on Day 14, which means that the twelve players that were left could join the opposite tribe if they wanted to. No one took the offer. (The twist was used again during Survivor: Cook Islands, with two players switching tribes.)

The biggest twist of the season was the fake merge. When only ten players were left, the usual time for a merge, the two tribes moved onto one beach, with a feast waiting for them. The two tribes thought they were merging, and Shii Ann Huang tried to align herself with members of the other tribe. At the next challenge they went to, however, the two tribes were told that they were living on one beach, but were not merged yet. That day, Shii Ann's tribe lost immunity, and she was voted off.

Host Jeff Probst said that he didn't like this season, and called it his least favorite. He said the season was mean-spirited and had a lot of hostility and ugliness, even calling Brian, Clay, Helen, and Jan "the least likable final four ever."[1]

Shii Ann was the only player this season to return in Survivor: All-Stars, where she placed 6th.

If more than one tribe or player wins reward or immunity, they are listed in order of finish, or alphabetically if it was teamwork, or where one player won and invited others, the players they invited are in brackets.

^ For the first time, the players would be bidding for items as tribes. Sook Jai and Chuay Gahn each got $1000 in American money.

^ In a twist, the Survivors' family members competed in an insect food eating challenge to see their loved one. Helen's husband Jim actually won the challenge and he spent 24 hours at the Chuay Jai camp with her.

^ In another twist, the players and their loved ones competed for immunity. Ted and his younger brother Aljuan won thus earning Ted immunity.